1. Field of the Invention
The present invention relates to wireless networks, and more specifically, to a method for selecting a channel in a wireless network.
2. Description of the Prior Art
Wireless networks are a popular field under development in modern technology. In a wireless network, a frequency band for receiving and transmitting signals can be divided into channels. For instance, a communication frequency band is divided into 12 channels according to the IEEE 802.11a standard, or into 14 channels according to the IEEE 802.11b standard.
A wireless network system generally includes more than one access point (AP), and each AP uses at least one channel. When an AP is turned on, it is required to search for at least one idle channel (i.e. a channel not being used by other APs) in the wireless network system in which it is located.
However in a wireless network system, channels generally overlap each other, so that a channel being used may interfere with neighboring idle channels. If the wireless network system has a plurality of idle channels, different channels may suffer from interferences of different degrees causing different APs to have different communication quality. Therefore, it is desirable to select an idle channel providing better communication quality among a plurality of idle channels.
Conventionally a method to select an idle channel involving detecting the interference on the idle channel is provided, in order to determine a communication quality value for the selected idle channel. If the quality value exceeds a predetermined threshold, the AP uses the corresponding idle channel to transmit signals, and if the quality value does not exceed the predetermined threshold, the AP continues detecting other idle channels until an idle channel having a communication quality value exceeding the threshold is found.
However, the aforementioned operation requires time for searching. In other words, the idle channel to be used cannot be determined immediately.